Conventional display devices are known e.g. from US 2010/0220295 A1, wherein the light guiding element is formed as a plane-parallel plate, with the result that both the front side and the rear side are in each case a planar surface. In this case, it is relatively easy to generate a large eyebox (the region of the imaging optical system in which the eye of the user can move wherein the user can always still perceive the output image). This is achieved by carrying out a sequential multiple outputting via the output grating which is not imaging.
However, if the light guiding element has a curved front side and/or a curved rear side, the difficulty arises that the light bundles guided between the two gratings in total reflection are influenced by the curved front side and/or the curved rear side, with the result that, after each reflection, there is a different state of the wave propagating on the basis of the light bundle.